Sylvania Tru-Aim MR16 Energy Saver - EYR
During the 1980s Sylvania rolled out an Energy Saving strategy across its entire light source portfolio. The tungsten halogen lamps were of course included, and several product categories were expanded to include new higher efficacy versions. First launched was a series of double ended linear sources, employing coiled-coil filaments and gas fillings of higher pressure and higher molecular weight to realise a wattage reduction of approximately 10%. A few years later low energy MR16 lamps were introduced, with the launch of this 42-watt rating to replace conventional 50W MR16 lamps. However in this case there is no real efficacy increase - the light output has just been reduced in proportion to the wattage

At this time Sylvania had no MR16 display lamp production in either its European or American factories, and the products were made the affiliated company Kondo Sylvania in Japan. This lamp thus shares many design features with the typical Japanese "JR" products of the time.

Unusually for such a low voltage and low wattage lamp, the filament is of a coiled-coil design. Although the coiled-coil does not bring about any substantial increase in luminous efficacy, it does permit the filament size to be reduced. A small filament is of great importance in such a compact reflector, because it helps to increase the optical efficiency of the system. It also leads to a filament of lower aspect ratio, such that the resulting beam has a more uniform light distribution.

The reflector design also shows an unusual feature in that the surface is peened around the outer perimeter. The purpose of this is simply to reduce glare from stray light rays being reflected from this part of the mirror surface.
Manufacturer: Kondo Sylvania
Lamp Power: 42 Watts  
Lamp Voltage: 12 Volts  
Lamp Current: 3.5 Amperes  
Cap Type: GX5.3 Rectangular glass base
Bulb Type: MR-51 MR-16 in eighths/inch
Bulb Finish: Open Front Dichroic Mirror
Filament Type: CC-6 Transverse coiled coil
Atmosphere: Krypton:Argon Bromine cycle
Luminous Flux: 800 (capsule flux)
Luminous Efficacy: 19.0 (capsule efficacy)
Peak Intensity: 7,070 candelas to half-peak intensity
Beam Distribution: 11.5° to half-peak intensity
Colour Temperature & CRI: CCT: 3000K CRI: Ra 100
Chromaticity Co-ordinates: CCx: 0.452 CCy: 0.409
Rated Lifetime: 4000 hours to 50% survival
Burning Position: Universal  
Overall Length: 44.45 mm 1 3/4"
Light Centre Length: N/A
Factory: Tokyo Japan
Date of Manufacture: July 1987 19
Original / Present Value: US $13.64 (1991) £11.28 (2008)
 
References: 1) Sylvania USA Brochure - "Tru-Aim Lamps" - December 1989
2) Sylvania USA Large Lamp Catalogue - 1986
3) Sylvania USA Large Lamp Price List - 1991